/**
 * \file pkcs11.c
 *
 * \brief Wrapper for PKCS#11 library libpkcs11-helper
 *
 * \author Adriaan de Jong <dejong@fox-it.com>
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 *
 *  This file is provided under the Apache License 2.0, or the
 *  GNU General Public License v2.0 or later.
 *
 *  **********
 *  Apache License 2.0:
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  **********
 *
 *  **********
 *  GNU General Public License v2.0 or later:
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  **********
 */

#include "nettls/pkcs11.h"

#if defined(MBEDTLS_PKCS11_C)

#include "nettls/md.h"
#include "nettls/oid.h"
#include "nettls/x509_crt.h"

#if defined(MBEDTLS_PLATFORM_C)
#include "nettls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free   free
#endif

#include <string.h>

void mbedtls_pkcs11_init(mbedtls_pkcs11_context* ctx)
{
    memset(ctx, 0, sizeof(mbedtls_pkcs11_context));
}

int mbedtls_pkcs11_x509_cert_bind(mbedtls_x509_crt* cert, pkcs11h_certificate_t pkcs11_cert)
{
    int ret = 1;
    unsigned char* cert_blob = NULL;
    size_t cert_blob_size = 0;

    if (cert == NULL) {
        ret = 2;
        goto cleanup;
    }

    if (pkcs11h_certificate_getCertificateBlob(pkcs11_cert, NULL, &cert_blob_size) != CKR_OK) {
        ret = 3;
        goto cleanup;
    }

    cert_blob = mbedtls_calloc(1, cert_blob_size);
    if (NULL == cert_blob) {
        ret = 4;
        goto cleanup;
    }

    if (pkcs11h_certificate_getCertificateBlob(pkcs11_cert, cert_blob, &cert_blob_size) != CKR_OK) {
        ret = 5;
        goto cleanup;
    }

    if (0 != mbedtls_x509_crt_parse(cert, cert_blob, cert_blob_size)) {
        ret = 6;
        goto cleanup;
    }

    ret = 0;

cleanup:
    if (NULL != cert_blob)
        mbedtls_free(cert_blob);

    return (ret);
}

int mbedtls_pkcs11_priv_key_bind(mbedtls_pkcs11_context* priv_key, pkcs11h_certificate_t pkcs11_cert)
{
    int ret = 1;
    mbedtls_x509_crt cert;

    mbedtls_x509_crt_init(&cert);

    if (priv_key == NULL)
        goto cleanup;

    if (0 != mbedtls_pkcs11_x509_cert_bind(&cert, pkcs11_cert))
        goto cleanup;

    priv_key->len = mbedtls_pk_get_len(&cert.pk);
    priv_key->pkcs11h_cert = pkcs11_cert;

    ret = 0;

cleanup:
    mbedtls_x509_crt_free(&cert);

    return (ret);
}

void mbedtls_pkcs11_priv_key_free(mbedtls_pkcs11_context* priv_key)
{
    if (NULL != priv_key)
        pkcs11h_certificate_freeCertificate(priv_key->pkcs11h_cert);
}

int mbedtls_pkcs11_decrypt(
    mbedtls_pkcs11_context* ctx, int mode, size_t* olen, const unsigned char* input, unsigned char* output, size_t output_max_len)
{
    size_t input_len, output_len;

    if (NULL == ctx)
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    if (MBEDTLS_RSA_PRIVATE != mode)
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    output_len = input_len = ctx->len;

    if (input_len < 16 || input_len > output_max_len)
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    /* Determine size of output buffer */
    if (pkcs11h_certificate_decryptAny(ctx->pkcs11h_cert, CKM_RSA_PKCS, input, input_len, NULL, &output_len) != CKR_OK) {
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);
    }

    if (output_len > output_max_len)
        return (MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE);

    if (pkcs11h_certificate_decryptAny(ctx->pkcs11h_cert, CKM_RSA_PKCS, input, input_len, output, &output_len) != CKR_OK) {
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);
    }
    *olen = output_len;
    return (0);
}

int mbedtls_pkcs11_sign(
    mbedtls_pkcs11_context* ctx, int mode, mbedtls_md_type_t md_alg, unsigned int hashlen, const unsigned char* hash, unsigned char* sig)
{
    size_t sig_len = 0, asn_len = 0, oid_size = 0;
    unsigned char* p = sig;
    const char* oid;

    if (NULL == ctx)
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    if (MBEDTLS_RSA_PRIVATE != mode)
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    if (md_alg != MBEDTLS_MD_NONE) {
        const mbedtls_md_info_t* md_info = mbedtls_md_info_from_type(md_alg);
        if (md_info == NULL)
            return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

        if (mbedtls_oid_get_oid_by_md(md_alg, &oid, &oid_size) != 0)
            return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

        hashlen = mbedtls_md_get_size(md_info);
        asn_len = 10 + oid_size;
    }

    sig_len = ctx->len;
    if (hashlen > sig_len || asn_len > sig_len || hashlen + asn_len > sig_len) {
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);
    }

    if (md_alg != MBEDTLS_MD_NONE) {
        /*
         * DigestInfo ::= SEQUENCE {
         *   digestAlgorithm DigestAlgorithmIdentifier,
         *   digest Digest }
         *
         * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
         *
         * Digest ::= OCTET STRING
         */
        *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
        *p++ = (unsigned char)(0x08 + oid_size + hashlen);
        *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
        *p++ = (unsigned char)(0x04 + oid_size);
        *p++ = MBEDTLS_ASN1_OID;
        *p++ = oid_size & 0xFF;
        memcpy(p, oid, oid_size);
        p += oid_size;
        *p++ = MBEDTLS_ASN1_NULL;
        *p++ = 0x00;
        *p++ = MBEDTLS_ASN1_OCTET_STRING;
        *p++ = hashlen;
    }

    memcpy(p, hash, hashlen);

    if (pkcs11h_certificate_signAny(ctx->pkcs11h_cert, CKM_RSA_PKCS, sig, asn_len + hashlen, sig, &sig_len) != CKR_OK) {
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);
    }

    return (0);
}

#endif /* defined(MBEDTLS_PKCS11_C) */
